A streamlined air baffle for efficiently directing air flow from a fan unit to a heat sink is disclosed. The streamlined air baffle has a top cover plate and a pair of side walls. The side walls are connected to the top cover plate. The top cover plate and one end of the side walls define an inlet. A curved surface of the top cover plate defines the outlet with the opposite ends of the side walls. The cross section area of the outlet is smaller than the cross section area of the inlet.